Oh God, please don't mention Rambos.
I was playing a few days ago on one of TWB's Hardcore Realism servers and a German MGer named Madjack was utterlty rapping my squad in the Barracks.
I got so mad I couldn't believe it.
Then learn new tactics to counter him.... every tactic has a weak spot.
If someone is running and gunning, then let them come to you and ambush their arse..... if someone is camping a bottleneck with an MG and killing your team, then either flank or start lobbing grenades around the corner.
Nobody has a clear advantage over anybody else unless you let them.
In regards to the Battlefield Commissions only being given to riflemen, while I understand the reasoning behind it, I also see some contradictions:
"Riflemen (not the elite ones) get little love and most people try to choose anything but them."
So we give the Riflemen the opportunity to do the exact same thing you're complaining about and pick something other than Riflemen.
Giving BC's to only riflemen will not prevent your problem of everybody picking the "Better" classes.... people will still be picking every other class and even if a riflemen boots them out of their spot due to a BC, that just means that person becomes a riflemen and the riflemen becomes their class and the same amount of semi-autos and SMG's are still on the map..... and if it goes to a round 3, then those new riflemen will have the chance to take their role back and throw the original rifleman back into rifleman status.... thus it doesn't exactly solve the problem as it just creates a similar problem where people with those slow machines will still complain that they only got to use a specific class one round while were still stuck using riflemen class for 2 rounds out of three and someone else will propose yet another idea to try and fix that.
I only use battlefield commissions to make sure the class I'm currently using doesn't get taken away and I just pick it again.... only once did I take a class from someone else with it.
But your idea did just made me think of something that might meet what you're trying to accomplish, but it's a little different so I'll post another thread......